1. Field of the Invention
The present invention relates to an optical device, an optical device fabrication method and a projector that includes the optical device.
2. Description of the Related Art
In these days, data projectors are used on many occasions as image projectors which project images including images of a screen and video images of a personal computer and further images based on image data which are stored in a memory card on to a screen. In these projectors, light emitted from a light source is collected on to a micromirror display element called a digital micromirror device (DMD) or a liquid crystal panel for projection of color images on to a screen.
Conventionally, the mainstream of these projectors has been those which utilize a high-intensity discharge lamp as a light source. In recent years, however, there have been made many developments and proposals on projectors that use as a light source light emitting diodes (LEDs), laser diodes, organic electroluminescent semiconductors or luminophors.
In these projectors, there is proposed a projector which includes a plurality of laser light sources and a plurality of collimator lenses that correspond to the plurality of laser light sources and in which excitation light that is emitted from the plurality of laser light sources via the plurality of collimator lenses is collected to be shone on to a luminescent material layer of a luminescent wheel via collective lenses so as to emit luminescent light from the luminescent material layer.
In a light source unit of this projector, an optical device using mirrors and lenses is used to combine optical axes of red, green and blue light so as to be guided to a light guiding device such as a light tunnel.
In addition, Japanese Unexamined Patent Publication (KOKAI) No. 2006-209832 discloses an optical device fabrication method in which a positional adjustment is carried out by employing a plurality of spacers of a predetermined thickness.
This optical device is such as to control the position of a movable member including, for example, an optical element of an optical head system of a compact disc player by driving a drive magnet of the optical head system.
In the optical device described in Japanese Unexamined Patent Publication (KOKAI) No. 2006-209832, in adjusting the height, a thickness resulting when the movable member is fastened by tightening screws changes in accordance with the number of spacers disposed. This changes the fitting amount of the screws, which requires a tightening torque to be adjusted every time the screws are tightened.